Penn has had a tumultuous 2009, which started on a high note with an Oscar win for his role in Milk. In late April however, the actor filed for legal separation from his wife of 13 years, actress Robin Wright Penn. The two reconciled and in May, Penn requested that the courts dismiss his separation petition.
It's believed that Penn is taking time off from his career to focus on family matters.
Production on Cartel, a crime drama about a father trying to protect his son after his wife is murdered by a Mexican drug syndicate, is expected to proceed with a new lead cast to replace Penn.
The Farrelly brothers face bigger complications with Stooges, which generated headlines when Penn, Jim Carrey and Benicio del Toro were announced as the stars. It seems unlikely that MGM would risk losing Carrey and del Toro to hold production until Penn returns to acting, but no formal announcement has yet been made. [Hollywood Reporter]